Musk has spent days bounding in and out of meetings, sitting in on phone calls, weighing resumes and traveling to Washington as Trump’s unofficial co-president.

Donald Trump announced Tuesday that the world's richest man, Elon Musk, will lead a new U.S. "government efficiency" group tasked with cutting federal waste, as the Republican president-elect added a series of seasoned figures and hard-liners to his incoming administration.

Elon Musk is backing Donald Trump’s transition co-chair Howard Lutnick to lead the Treasury Department, touting the billionaire CEO of Cantor Fitzgerald as a potential secretary who “will actually enact change” from the most powerful economic post in Trump’s cabinet.

Musk’s moves since the election suggest the Tesla CEO will be heavily involved in the Trump administration’s ‘revolution,’ as he calls it.

Musk spent millions to help Trump get elected and was one of his most vocal supporters. But he could butt heads with Trump over China.

US voters re-elected Donald Trump. At the moment, it looks like they also elected Elon Musk. He's acting like a shadow president, Peter Kafka writes.

Chris Hayes says Trump's 'co-president' Elon Musk may be wearing out his welcome after the president-elect joked he couldn't get rid of the billionaire